Incandescent lamp and similar device



Jan. 15, 1935. wRlGHT 1,988,290

INCANDESCENT LAMP AND SIMILAR DEVICE Filed April 15, 1933 [N YEN TUE EANZEL K.WRZ5H 2',

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Patented Jan. 15, 1935 PATENT OFFICE 1,288,290 INCANDESCENT LAMP AND snmma nsvrcs Daniel K. Wright, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Application April 15, 1933, Serial No. 866,334

8 Claims.

My invention relates to electric incandescent lamps and similar devices comprising an electric energy translation element, such as a illament, enclosed or sealed in a bulb or envelope.

6 Heretofore, the practice has been to provide such a device with a separate base united to its hermetically sealed glass bulb or envelope by cement or other means; this bulb supporting the internal "mount" of the lamp or the like,

1 comprising the translation element and its supporting structure inside the bulb. Typically, the unitary base structure not only serves as a means for mounting the lamp, but also includes terminals or contacts connected to conductors leading into the bulb through the glass to the translation element inside.

Very commonly, the base comprises a metal shell or sleeve, which receives and holds the end of the bulb (with the aid of suitable ce- 90 ment) and is provided with engagement means (such as screw threads or bayonet pins) for securing the base in a socket or othersupport. Such a base sleeve may itself form one of the base terminals; or' it may not. In addition, such a base usually has one or more terminals or contacts exposed at one end thereof, con- ,nected by one or more leads" to the translation device, and suitably insulated from the sleeve. However, a great many forms of bases have been used, some of which differ from the more usual illustrative types just described. For example, there .are double ended tubular lamps, with a base or terminal device at each end.

According to my invention, as distinguished from the practice above mentioned, the internal "mount" of the lamp or the like is mounted on the base or terminal device itself, or a portion thereof, independently of the attachment of the bulb to the base. Thus the mount is supported directly by such base or device, instead of through the medium of the bulb, as heretofore. Also, the glass bulb wall may be sealed directly to the base or terminal device by fusion or thermal softening, so that the base becomes an integral part of the lamp-even, in-

deed, a part of the enclosing envelope itself. The current leads need no longer pass through the glass envelope; the usual separate basing operation can be eliminated; and it becomes much easier to locate the translation element accurately and uniformly with reference to the engagement means of the base. This is specially advantageous for lamps used with light projection devices such as reflectors, proiectors with lenses,etc.; since by accurately locating their sockets or other lamp holding means according to definite standards, standard lamps constructed according to my invention can be eillcientiy used in them without any necessity or provision for focussing adjustments. Moreover, the lamp 5 is much simpler and stronger, and less expensive to make.

In my pending application Serial No. 588,485, filed January 23. 1932, of which this application is a continuation in part, I have shown and described one species or type of lamp embodying my invention, as well as a method for manufacturing such lamps. Other species of the invention, at present preferred by me for general use, are illustrated in the accompanying drawing and described hereinafter. In such species, I prefer to employ a metal lamp base resembling the common types hereinbefore described, comprising a metal shell and provided with terminal means exposed at the end of the base. To such a metal base I seal the glass bulb directly, by fusion or thermal softening; and on it I mount directly the filament supporting means, independently of the attachment of the bulb thereto. Various other features and advantages of the invention will appear from the following description of species thereof, and from the drawing.

In the drawing, Fig. 1 is a perspective view of a lamp conveniently embodying my invention; Fig. 2 is a vertical sectional view through a portion thereof, illustrating a form of construction representing one species of my invention; Figs. 3, 4 and 5 are similar sections illustrating other species of the invention; and Fig. 6 is a vertical sectional view illustrating yet another species.

The device shown in Fig. 1 is an incandescent electric lamp having as'its electric energy translation element a filament 10 within a glass bulb 11, connected between wires 12 and 13 attached to its ends, and additionally supported, at intermediate points, by wires 14 whose ends are fused into a glass head 15, itself fused to the wire 13. To increase the rigidity of the supporting structure, a brace wire 16 fused into the head 15 at one end is welded at its other end to the wire 12.

- In the present instance, the wires 12, 13 not only support the filament 10, but also serve as its current leads. The mount, comprising the filament 10 and its supporting means just described, is attached directly to a base 1'1, here of an Edison or screw type, having a sheet metal screw shell 17a that serves as one base contact. and having another base contact 18 exposed at its lower end, but insulated from the shell. The

against which the end of the bulb 11 abuts and is sealed, with an upstanding lip 17c around this seat. In the sealing operation, the end of the bulb may be pressed while hot against the heated seat 17b, and thereby also sealed to the inner surface of the lip 17c. The seat 17b may be made of any radial width desired to enable the base shell 17a to take a bulb neck that will admit a filament or a mount" larger than the main (threaded) portion of the shell 17a. The lip 17c affords additional adhesion area for the glass and protects the joint, but is of such small height (e. g of a magnitude comparable to the thickness of the glass) that it does not shade or cut off useful light from the filament 10.

In mounting the filament supporting structure on the base 17, the wire 12 may be attached by welding to a diaphragm or web 17d across the interior of the shell, at its bottom. The wire 13 extends to an opening in this portion 17d and is embedded and secured in a fused body of glass which closes and seals the opening, but the end of the wire 13 may be exposed outside to serve as a center contact 18. The seal 18' is here shown as a tip formed by the residue of a glass exhaust" tube 19 sealed to the shell bottom 17d, and sealed off (after use) around the wire 13.

The portion of the wire 13 embedded in the glass is preferably made of material similar to the shell 17a, or such as heretofore used for incandescent lamp ieads sealed in glass.

In the construction shown in Fig. 3, only the portions of the base shell 17 that are sealed to glass are made of the special material used for the whole shell in Fig. 2, the rest being of ordinary metal like brass that is less expensive and easier to work. The upper and lower ends of the screw threaded brass shell 20 are flanged inward, and to their flanges are welded (gas-tight) apertured discs or flat rings 21, 22, of the special glass-sealing metal. The upper disc 21 is externally lipped to afford a bulb-end abutting seat similar to that of Fig. 2, and the lower disc 22 forms the bottom diaphragm of the screw shell.

As shown in Fig. 4, the upper edge of the base shell 23 tapers down to a very thin section about which the glass of the bulb wall 11 is sealed. With this construction, materials for bulb and shell'are, not greatly restricted; e. g., to a shell 23 of copper, which wets well to glass, may be sealed a bulb 11 of hard glass whose thermal coefiicient of expansion is much lower than that of copper. The thin edge section of theshell 23 permits such a combination. The shell 23 has an inward-recessed bottom with a central opening surrounded by an outstanding flange or nipple 24, whose wall tapers to a very thin edge. A metal cap 25 with a corresponding tapered edge is attached to the nipple 24 by a ring of glass 26 sealed over the edges of both parts. In its bottom, the cap 25 has a central 'hole 27, adapted to serve as an exhaust opening.

The mount wire 12 is attached to the shell 23, about as in Figs. 2 and 3, while the lead 13 extends down into the cap 25 and is there bent around the hole 27 and secured by solder 28.

The construction shown in Fig; 5 diifers from that of Fig. 4 in that the bulb wall is only sealed to the inside surface of the thinned upper edge of the shell 23a, and in that the center contact construction resembles that of Figs. 2 and 3; i. e., the fused glass seal 29 around the lower end of the wire 13 is formed by sealing off a glass exhaust tube 30 whose end has been sealed over the edge of the nipple 24 like the glass ring 26 in Fig. 4.

The construction shown in Fig. 6 has a bayonet type of base instead of a screw base, as in Figs. 1-5, otherwiseit most nearly resembles Fig. 2. Here the lower end of the lamp bulb 11 is sealed to the inside of a shell 31 provided with bayonet pin projections 32, and made of special metal such as that employed for the shell 17 in Fig. 2. The bottom web or -diaphragm 33 of the shell 31 has two openings in which are sealed the fused glass bcdiesor beads 34-34. The two mount .wires 12, 13 are embedded and secured in the beads 3434, with their ends exposed outside to serve as end contacts. Either (or both) of the beads 34-34 may be formed by fusing down the residue of an exhaust tube (not shown) as described above in connection with Fig. 2.

The iron chromium alloy (hereinbefore referred to) which I prefer is one marketed by the Allegheny Steel Co. as Allegheny 55, of which the following is a typical percentage-by-weight analysis:

Iron 67. 5 to 71. 5 Chromium 26 to 30 Manganese under 1 Nickelunder .6 Silicon under .6 Carbon under .25 Sulphur under .025 Phosphorusunder .025

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electrical device comprising a bulb; a unitary base structure or termina device, by which the lamp is mounted,'sealed to the wall of said bulb and having an exhaust opening for the bulb therethrough; and a mount in said bulb, including an electric energy translation element with its supporting means and current lead wires, mounted on said base structure independently of the attachment of the bulb to said base structure with one of the lead wires extending to said exhaust opening; and a fused seal sealing said exhaust opening and securing said current lead wire.

2. An electrical device comprising a bulb; a unitary base structure or terminal device, by which the lamp is mounted and which embodies its contact terminals, sealed to the wall of said bulb and having an exhaust opening for the bulb through one of said contact terminals; and a mount in said bulb, including an electric energy translation element and its supporting means and current lead wires, mounted on said base structure independently of the attaclunent of the bulb to said base structure, with one of said lead wires extending to said exhaust op'en-' ing; and a fused seal securing said current lead -76 wire to the apertured contact terminal and sealing the exhaust opening.

3. An electrical device comprising a unitary base having an exhaust opening in its bottom; a bulb or envelope sealed to said base structure; a filament with supporting means therefor mounted on said base structure independently of the bulb, and with a lead wire extending through said exhaust opening; and a residue of exhaust tubing sealed to the edge of said opening and also fused and sealed around said lead, but leaving the end of the latter exposed as an external contact.

4. An electrical device comprising a metal base shell; a disc of metal to which glass is more readily sealable attached to said shell; a glass bulb or envelope abutting endwise against said disc and sealed thereto; and a filament with supporting means therefor mounted on said metal base shell independently of the bulb.

5. An electrical device comprising a metal base shell; a disc of metal to which glass is more readily sealable attached to said shell and having an upstanding lip; a glass bulb or envelope abutting endwise against said disc and sealed thereto and to the inside of said lip; and a filament with supporting means therefor mounted on said metal base shell independently of the bulb.

6. An electrical device comprising a metal base structure, including a shell with an inward flanged bottom opening, and an apertured bottom disc of metal to which glass is more readily sealable attached and sealed to the flange around said bottom opening; a glass bulb or envelope sealed to said base structure; a body of glass sealed to said bottom disc at its aperture and sealing the latter; and a filament with supporting means therefor mounted on said metal base shell independently of the bulb, including an external contact lead sealed through said body of glass.

7. The method of manufacturing incandescent lamps or the like comprising a base member having an aperture therethrough and a glass exhaust tube having an end sealed to the rim of said aperture, which comprises attaching a mount comprising an energy translation element and a plurality of supporting lead wires to said base member, one of said lead wires extending into said exhaust tube, sealing the end of a glass bulb to said base member, and after use of said exhaust tube, fusing and sealing it around said lead wire.

8. The method of manufacturing incandescent lamps or the like comprising a base member having an aperture therethrough and a glass exhaust tube having an end sealed to the rim of said aperture, which comprises attaching a mount comprising an energy translation element around a portion of said lead wire, the end ofsaid lead wire extending through the seal formed from said tube to constitute a terminal for the lamp.

DANIEL K. WRIGHT. 

